 /*******************************************************************************
  * Copyright (c) 2004, 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.internal.presentations;

 import org.eclipse.jface.action.Action;
 import org.eclipse.ui.IEditorPart;
 import org.eclipse.ui.IPersistableEditor;
 import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.IWorkbenchWindow;
 import org.eclipse.ui.PartInitException;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.XMLMemento;
 import org.eclipse.ui.internal.IWorkbenchConstants;
 import org.eclipse.ui.internal.WorkbenchMessages;
 import org.eclipse.ui.internal.WorkbenchPage;
 import org.eclipse.ui.internal.dialogs.DialogUtil;
 import org.eclipse.ui.presentations.IPresentablePart;
 import org.eclipse.ui.presentations.IStackPresentationSite;

 /**
  * This convenience class provides a "New Editor" system menu item that
  * opens another editor of the same type as the current editor, on the same input.
  * Presentations can use this to add a "New Editor" item to their system menu.
  *
  * @since 3.1
  */
 public final class SystemMenuNewEditor extends Action implements ISelfUpdatingAction {

     private IStackPresentationSite site;
     private IPresentablePart part;

     /**
      * Creates a new instance of the action
      *
      * @param site the presentation site
      */
     public SystemMenuNewEditor(IStackPresentationSite site) {
         this.site = site;
         setText(WorkbenchMessages.PartPane_newEditor);
     }

     /**
      * Disposes the action.
      */
     public void dispose() {
         site = null;
     }

     public void run() {
         if (part != null) {
             // the site doesn't give access to the page or the active editor,
 // so we need to reach
 IWorkbenchWindow window = PlatformUI.getWorkbench()
                     .getActiveWorkbenchWindow();
             if (window != null) {
                 IWorkbenchPage page = window.getActivePage();
                 if (page != null) {
                     IEditorPart editor = page == null ? null : page
                             .getActiveEditor();
                     if (editor != null) {
                         String editorId = editor.getSite().getId();
                         if (editorId != null) {
                             try {
                                 if (editor instanceof IPersistableEditor) {
                                     XMLMemento editorState = XMLMemento
                                             .createWriteRoot(IWorkbenchConstants.TAG_EDITOR_STATE);
                                     ((IPersistableEditor) editor)
                                             .saveState(editorState);
                                     ((WorkbenchPage) page).openEditor(editor
                                             .getEditorInput(), editorId, true,
                                             IWorkbenchPage.MATCH_NONE,
                                             editorState);
                                 } else {
                                     page.openEditor(editor.getEditorInput(),
                                             editorId, true,
                                             IWorkbenchPage.MATCH_NONE);
                                 }
                             } catch (PartInitException e) {
                                 DialogUtil.openError(page.getWorkbenchWindow()
                                         .getShell(), WorkbenchMessages.Error, e
                                         .getMessage(), e);
                             }
                         }
                     }
                 }
             }
         }
     }

     /**
      * Sets the target of this action to the given part.
      *
      * @param presentablePart
      * the target part for this action, or <code>null</code> if
      * there is no appopriate target part
      */
     public void setTarget(IPresentablePart presentablePart) {
         this.part = presentablePart;
         setEnabled(presentablePart != null);
     }

     /* (non-Javadoc)
      * @see org.eclipse.ui.internal.presentations.ISelfUpdatingAction#update()
      */
     public void update() {
         setTarget(site.getSelectedPart());
     }

     /* (non-Javadoc)
      * @see org.eclipse.ui.internal.presentations.ISelfUpdatingAction#shouldBeVisible()
      */
     public boolean shouldBeVisible() {
         return true;
     }
 }

